Introduction. The most important problems of clinical characterization and timely diagnosis of a new coronavirus infection COVID- 19 have been identified. The detection and treatment of patients with COVID-1 9 in the domestic health care system are carried out according to the Provisional Methodical Recommendations “Prevention, Diagnostics and Treatment of New Coronavirus Infection”. Its basic clinical manifestations are characterized by typical symptoms of acute respiratory viral disease: fever, dry cough, stuffy nose, headache, etc.Objective. To study the nature of clinical manifestations of new coronavirus infection COVID-1 9, associated with delta strain of SARS-CoV-2 coronavirus with moderate and severe course.Materials and methods. We analyzed the course of the disease in 50 patients treated as inpatients at Saransk Covid Hospital. Questionnaires to analyze complaints and anamnesis of diseases, data of medical records of in-patients were used. We used visual analog scale (VAS) to estimate the intensity of non-specific neurological disturbances, decreased sense of smell, taste and hearing, where 0 point means no neurological disturbance, 10 points – expressed disturbance. The presented data allowed to analyze the general, nonspecific and specific neurological manifestations of the new coronavirus infection COVID- 19 in the acute period in patients with moderate and severe course and to reveal their peculiarities.Results. At a moderately severe course of the disease, the characteristic symptoms of respiratory infection in combination with depressed mood and anxiety predominated. Of nonspecific neurological disorders, sleep disturbances, dizziness, and of specific manifestations, impaired sense of smell and taste prevailed. At a severe course the above symptoms were joined by myalgia, headache, dyspnea and shortness of breath, gastrointestinal disorders.Conclusions. The severity of the course of COVID-1 9 coronavirus infection, associated with the delta strain of SARS-CoV-2 coronavirus, is determined by the severity of the generalized manifestations, involvement of the lower respiratory tract, gastrointestinal disorders.